have if possible less strategic subtlety than the ordinary clever criminal. But that rather deep quality seems very rarely to go with the criminal make-up. Look at Crippen. He was a very clever criminal as they go. He solved the central problem of every clandestine murder, the disposal of the body, with extreme neatness. But how far did he see through the game? The criminal and the policeman are often swift and bold tacticians, but neither of them is good for more than a quite simple plan. After all, it's a rare faculty in any walk of life.'
'One disturbing reflection was left on my mind,' said Mr. Cupples, who seemed to have had enough of abstractions for the moment, 'by what we learned today. If Marlowe had suspected nothing and walked into the trap, he would almost certainly have been hanged. Now how often may not a plan to throw the guilt of murder on an innocent person have been practised successfully? There are, I imagine, numbers of cases in which the accused, being found guilty on circumstantial evidence, have died protesting their innocence. I shall never approve again of a death-sentence imposed in a case decided upon such evidence.'
